Antineoplastic Agents. 554. The manitoba bacterium Streptomyces sp.
ABSTRACT A Streptomyces sp. isolated from riverbank soil in Manitoba, Canada, was found to contain two cancer cell growth inhibitories: diazaanthraquinone 1 and 3-(hydroxyacetyl)indole (8). The structures were determined by interpretation of data from HRMS, UV, and high-field (400 MHz) NMR experiments. The red-colored diazaanthraquinone 1 and 3-(hydroxyacetyl)indole (8) were found to inhibit (0.1-3 microg/mL) growth of a minipanel of human cancer cell lines and P388 lymphocytic leukemia cells. Diazaanthraquinone 1 was also found to inhibit growth of the bacteria Streptococcus pneumoniae and Neisseria gonorrheae. However, three companion constituents, cyclo-Pro-Leu (5), cyclo-Pro-Phe (6), and cyclo-Pro-Val (7), did not inhibit cancer cell growth.